The present invention relates to an electronic timepiece for Islamites and, more particularly, to an electronic timepiece which calculates the five salat times.
The Islamite prayer is normally conducted five times a day at a predetermined time. The salat time changes depending on the location on the earth and the date of a year. This is because the salat time is determined depending on the sunrise time and the sunset time. Thus, it is required to provide an electronic timepiece which automatically calculates the salat time in accordance with the introduced information relating to the location on the earth.
An electronic timepiece has been proposed, in U.S. Pat. No. 4,253,169, "Electronic Calculation Watch with Digital Display" by Ibrahim M. Salah issued on Feb. 24, 1981, wherein the operator introduces the data information and the latitude and longitude situation information for obtaining the prayer time. The system calculates the sunrise and sunset time through the use of the introduced situation information and the date information. Since the system is constructed to calculate the sunrise and sunset time through the use of the latitude data and the longitude data, the system becomes inevitably complicated. Thus, the electronic timepiece of a compact size can not be produced.
Accordingly, an object of the present invention is to provide an electronic timepiece of a compact size which automatically calculates the prayer time for the Islamites.
Another object of the present invention is to provide an electronic timepiece which provides an alarm display at each salat time.
Still another object of the present invention is to provide an electronic timepiece for the Islamites, which ensures simple operation.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a read only memory is installed in an electronic timepiece which stores the salat time information in a plurality of preselected cities during a year. When the operator introduces the city information and the date information into a control system of an electronic timepiece of the present invention, the control system functions to address a predetermined memory section in the read only memory for reading out the memorized salat time information. The thus read out salat time information is utilized to signal each salat time. In a preferred form, the data information is automatically obtained from the calendar counter included in the electronic timepiece. Therefore, the operator is required only to introduce the city information.
An embodiment of an electronic timepiece of the present invention performs the following operations.
(1) Normal timepiece operation wherein the electronic timepiece displays the hour information, minute information and second information; PA0 (2) Auto-calendar operation wherein the electronic timepiece displays the year information, month information, date information and day information; PA0 (3) Salat time alarm operation wherein the electronic timepiece provides an alarm sound and/or an alarm display at each of the five prayer times a day; PA0 (4) Prayer condition display operation wherein the electronic timepiece displays whether it is the prayer time or it is a time waiting for the next prayer, and wherein the electronic timepiece displays the salat number in a day; and PA0 (5) City selection and city display operation, wherein the electronic timepiece displays the city code number selected by the operator, the city code number being assigned to each of a plurality of preselected cities in the world.
The five salat times are determined in the following way in accordance with the sunrise time and the sunset time. EQU FIRST SALAT (FAJR)=(sunrise time)-A.
where: one hour .ltoreq.A.ltoreq.two hours. EQU SECOND SALAT (ZUHR)=[(sunrise time)+(sunset time)]/2. EQU THIRD SALAT (ASR)=[(second salat time)+(sunset time)]/2.
or EQU THIRD SALAT (ASR)=(second salat time)+B.
where: B=three hours. EQU FOURTH SALAT (MAGRIB)=sunset time. EQU FIFTH SALAT (ISHA)=(sunset time)+C.
where: C=one hour and thirty minutes.
In an embodiment of the present invention, the constant A for determining the first salat (Fajr) time is selected at one (1) hour. The third salat (Asr) time is obtained by the calculation, (second salat time)+(three hours (3)).